JP2795576B2 - Synchronous motor rotor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotor for a synchronous motor, and more particularly, to a rotating shaft, a plurality of permanent magnets radially arranged around the rotating shaft, and a plurality of permanent magnets disposed between adjacent permanent magnets. The present invention relates to an improvement in a rotor structure including a rotor core including a plurality of yoke members forming magnetic poles of a rotor and locking means for locking a plurality of permanent magnets between adjacent yoke members at predetermined radial positions.

[0002]

2. Description of the Related Art A rotor of a synchronous motor having a rotor core structure in which a plurality of permanent magnets are radially arranged around a rotating shaft and a plurality of magnetic poles are formed by yoke members arranged between adjacent permanent magnets. Already known. Generally, in this type of rotor, each permanent magnet and yoke member are fixed in the rotor core as follows. That is, an outer hook and an inner hook are formed on the outer peripheral portion and the inner peripheral portion of the side surface of the yoke member for holding the permanent magnet, respectively, and the permanent magnet is positioned and fixed in the radial direction by the outer hook and the inner hook. Each yoke member is fixed to annular end plates arranged at both axial ends of the rotor core by tie rods penetrating the yoke members in the axial direction. After mechanically fixing the permanent magnet and the yoke member in this way, the assembled rotor core is subjected to a resin impregnation step for mutually fixing the members.

[0003] In a rotor having such a structure, particularly in the case of a synchronous motor rotating at high speed or a high torque type synchronous motor in which a plurality of rotor cores are combined in the axial direction, a centrifugal force or a reaction force from a driving partner causes. The bending torque causes the rotating shaft and the tie rod to bend outward in the radial direction, and the gap between the outer peripheral surface of the yoke member and the inner peripheral surface of the stator surrounding the rotor fluctuates. And the stator may come into contact.
Therefore, for example, in a rotor having a multi-stage structure, a circular plate having a through hole for inserting the rotation shaft at the center and a rod insertion hole at the same position as the tie rod arrangement is inserted at the boundary of each stage. In general, the tie rod is mechanically fixed and held to increase the rigidity of the rotor core.
FIG. 6 shows an example of a rotor having such a structure. FIG. 6 shows a rotating shaft 1, a rotor core 2, a permanent magnet 3, a yoke member 4, a tie rod 5, an end plate 6, an annular plate 7, an outer hook 8 of the yoke member 4, and an inner hook 9 of the yoke member 4. It is.

[0004]

In the conventional rotor having the above construction, the outer peripheral surface of each yoke member has a magnetic flux distribution in a gap between the yoke member and the inner peripheral surface of the stator having a sinusoidal waveform with respect to the rotation angle. As shown, it is formed in a predetermined arc shape. Therefore, when the number of poles, that is, the number of yoke members is small, or when the permanent magnet is thin, if the arc shape of the outer peripheral surface of the yoke member is ideal, the end of the arc cannot cover the outer peripheral surface of the adjacent permanent magnet. Therefore, it may be difficult to form the outer hook. However, in the above-described conventional rotor, the fixing of the permanent magnet to the outside in the radial direction in particular depends on the outer hook provided on the yoke member. In such a case, in order to increase the reliability of the motor, the outer hook is formed at the expense of obtaining an ideal sine wave, but the performance is deteriorated due to uneven rotation. May be induced.

SUMMARY OF THE INVENTION The present invention has been made in order to solve such a problem, and has been devised and improved. It is an object of the present invention to provide a synchronous motor having the above structure, in which an outer hook for holding a permanent magnet on a yoke member of a rotor core is provided. Even when the rotor cannot be formed, it is possible to provide a synchronous motor rotor that can fix and hold a plurality of permanent magnets against an external force outward in the radial direction, has high rigidity and balance, and has high reliability. .

[0006]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a rotating shaft, a plurality of permanent magnets radially arranged around the rotating shaft and extending in the axial direction, and a magnet. A rotor core comprising a plurality of yoke members, each of which is provided between adjacent permanent magnets by laminating thin plates of material in the axial direction and each forming a magnetic pole of the rotor, and a plurality of permanent magnets disposed between adjacent yoke members. A synchronous motor rotor having locking means for locking at a predetermined position in the radial direction,
The locking means is made of a non-magnetic material, and is provided at a center portion thereof and has an insertion hole into which the rotating shaft is inserted, and a plurality of insertion holes which are arranged around the insertion hole and into which the permanent magnet can be inserted. And at least one annular plate member inserted into the rotor core at a predetermined position between the laminated structures of the yoke members, wherein the engagement hole of the annular plate member is At a position substantially matching each of the plurality of permanent magnets of the rotor core, the rotor core is formed so as to penetrate an annular plate member having a peripheral edge portion capable of contacting at least a radially outer peripheral surface of the permanent magnet ; The yoke member has a radius of the permanent magnet.
While having a shape that does not engage in the direction outer peripheral surface, the synchronization which the peripheral edge portion of said locking hole of said annular plate member, characterized in that to prevent the displacement of the radially outward of the permanent magnet An electric motor rotor is provided. Furthermore, the present invention
In the synchronous motor rotor, the annular plate member
The peripheral portion of the locking hole is continuous in the circumferential direction of the annular plate member.
The synchronous motor rotor defined by the
provide. Further, the present invention provides a synchronous motor
Wherein the rotor is in the axial direction of the rotor core.
The permanent magnet and the yoke member, which are arranged at both ends, are sandwiched.
Holding a pair of end plates, wherein the locking means is
Substantially aligned with each of the plurality of permanent magnets of the taco
At a position, has a peripheral wall portion capable of contacting the outer peripheral surface of the permanent magnet.
Further comprising a plurality of locking recesses formed in each of the end plates.
To provide a synchronous motor rotor.

[0007]

When the rotating shaft is inserted into the insertion hole of the annular plate member and the annular plate member is inserted into the rotor core at a predetermined position between the laminated structures of the yoke members, the plurality of permanent magnets of the rotor core are circularly inserted. The plurality of locking holes of the annular plate member are arranged so as to penetrate each of the locking holes. At this time, the peripheral portion of each locking hole contacts at least the radially outer peripheral surface of each permanent magnet. Accordingly, the annular plate member is held in the radial direction by the engagement between the insertion hole and the rotating shaft, and the plurality of permanent magnets are further radially outwardly provided by the peripheral portions of the locking holes of the annular plate member. Is prevented from being displaced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to the accompanying drawings. 1 to 3 show a rotor according to a first embodiment of the present invention, FIG. 4 shows a rotor according to a second embodiment of the present invention, and FIG. 5 shows a rotor according to a third embodiment of the present invention. In all the drawings, the same components are denoted by the same reference numerals.

Referring to FIGS. 1 and 2, a first embodiment of the present invention will be described.
The rotor of the synchronous motor according to the embodiment includes a rotating shaft 10 and a plurality (six in the example in the figure) of permanent magnets 12 (hereinafter simply referred to as magnets 1) having a substantially rectangular cross-section arranged radially around the rotating shaft 10.
2), and a rotor core 16 including a plurality of (six in the example in the figure) yoke members 14 (hereinafter simply referred to as the yokes 14) disposed between the adjacent magnets 12 and having a substantially fan-shaped cross section.
And The magnet 12 extends as a continuous body in the axial direction over substantially the entire length of the rotor core 16. York 14
Is formed by stacking silicon steel plates in the axial direction, and the magnet 12
To form the magnetic poles of the rotor. The side surface of each yoke 14 and the side surface of the adjacent magnet 12 are in close contact with each other. An inner hook 18 is provided in the vicinity of the inner peripheral portion of the side surface of the yoke 14 so as to protrude in the circumferential direction. In this embodiment, since the magnet 12 is thin, no outer hook is formed on the yoke 14 unlike the conventional rotor core (FIG. 6) (see FIG. 2).

At both ends in the axial direction of the rotor core 16, annular end plates 20 are arranged. Each end plate 20 is shrink-fitted and fixed to the rotating shaft 10. Further, the rotor core 16
Each of the yokes 14 has one through hole 22 (FIG. 2) penetrating in the axial direction at a substantially central portion thereof.
The tie rods 24 are inserted into the respective 2. Each tie rod 24 is fixed to each end plate 20 at both ends thereof through holes (not shown) provided in each end plate 20 at positions matching the through holes 22 of each yoke 14.

As shown in FIG. 1, each yoke 14 of the rotor core 16 is divided into two parts by an annular plate 26 at a substantially intermediate position in the axial direction. In other words, the rotor core 16 shown in FIG. 1 is obtained by stacking the yoke 14 having a predetermined reference length in two stages in the axial direction, and therefore, the rotor shown in FIG. It has become.
The annular plate 26 is a thin plate member made of a non-magnetic material such as stainless steel. As shown in FIG.
Is provided with an insertion hole 28 for inserting the. The inner diameter of the insertion hole 28 is substantially equal to the outer diameter of the rotating shaft 10, and when the annular plate 26 is inserted between the yokes 14 of the respective stages of the rotor core 16, the annular plate 26 surrounds the rotating shaft 10. Does not move in the radial direction. Further, the annular plate 26 is provided with the insertion hole 2.
8, six locking holes 30 are provided at equal intervals in the circumferential direction on one circumference concentric with the insertion hole 28. Lock hole 3
Numeral 0 has a rectangular peripheral portion 30a that is substantially the same as the cross section of the magnet 12 of the rotor core 16, and is formed at a position substantially matching the arrangement of the six magnets 12, respectively. Therefore, each magnet 1 radially arranged in the rotor core 16
The reference numeral 2 penetrates through each of the locking holes 30 of the annular plate 26 inserted between the yokes 14 of each step, and is locked at a predetermined position in the radial direction by the locking holes 30. Therefore, the plurality of magnets 12 are fixedly held by the annular plate 26 even in a radially outward direction due to centrifugal force or the like.

Further, since the locking holes 30 for the magnets 12 are formed through the annular plate 26 as described above, it is possible to configure the magnets 12 as a continuous body in the axial direction in a multi-stage rotor. , The number of magnets 12 is reduced. Therefore, the rotor according to the present invention also has an effect of reducing the manufacturing cost of the rotor. Further, FIG.
As shown in the figure, the annular plate 26 inserted at a substantially intermediate position in the axial direction between the yokes 14 at the respective stages of the rotor core 16 can tightly fit the tie rods 24 between the adjacent locking holes 30. Six rod support holes 32 are provided in alignment with each tie rod 24. Therefore, each tie rod 24 passes through each rod support hole 32 of the annular plate 26 at a substantially intermediate position in the axial direction of the rotor core 16. Thus, each yoke 14
It is supported by a ring plate 26 via a tie rod 24 and fixed to each end plate 20.

[0013] The rotor core assembly constructed as described above is mutually fixed to each other by a resin impregnating step as in the prior art. Thereby, the magnet 12 and the yoke 14
Are securely fixed in the radial direction and the circumferential direction in the rotor core 16, and a high rigidity of the rotor core assembly is obtained.

Referring to FIG. 4, the rotor according to the second embodiment of the present invention, like the rotor according to the first embodiment, includes a rotating shaft 10 and a plurality of magnets radially arranged around the rotating shaft 10. The rotor core 36 includes a plurality of yokes 14 disposed between adjacent magnets 34, and an annular plate 26 that divides the yoke 14 of the rotor core 36 at a substantially intermediate position in the axial direction. Unlike the magnet 12 of the first embodiment, the magnet 34 of the rotor core 36 has a length slightly protruding from both axial ends of the rotor core 36. Each end plate 38 disposed at both ends in the axial direction of the rotor core 36 has a plurality of locking recesses 40 formed in the surface facing the yoke 14 in the axial direction at positions matching the magnets 34. Therefore, in this embodiment, the rotor core 36
The plurality of magnets 34 are engaged with each of the locking holes 30 of the annular plate 26 inserted at a substantially intermediate position in the axial direction of the rotor core 16 and each of the end plates 38 disposed at both axial ends of the rotor core 36. It is locked at a predetermined position in the radial direction by the recess 40. Therefore, each magnet 34 is fixedly held by the annular plate 26 and each end plate 38 against an external force in a radially outward direction due to a centrifugal force or the like. In this embodiment, the locking recess 40 of each end plate 38 can be replaced by a hole penetrating each end plate 38 in the axial direction.

Referring to FIG. 5, the rotor according to the third embodiment of the present invention includes a four-stage rotor core 42 having twice the number of stages as the rotor according to the first embodiment. The rotor core 42 moves the yoke 14 having the reference length in the axial direction by four.
The annular plates 26 are formed by stacking on the steps, and the annular plates 26 are inserted at the boundaries between the steps. Each magnet 44 of the rotor core 42 is
In the figure, the rotor core 42 is divided at a substantially intermediate position in the axial direction, but may be formed as a continuous body over the entire length of the rotor core 42. In each case, each magnet 44 passes through each locking hole 30 of the annular plate 26 inserted into the rotor core 42 and is locked at a predetermined position in the radial direction by the locking hole 30. Therefore, each magnet 44 is connected to the annular plate 2 against external force in the radial direction outward due to centrifugal force or the like.
6 are fixedly held. Thus, the annular plate 2
6, the length of the magnet used for the rotor can be selected, and the production cost can be optimized particularly for a multi-stage or long rotor. . It is needless to say that this embodiment can be combined with the end plate 38 of the second embodiment to further enhance the locking effect of the magnet.

In each of the above embodiments, the magnet locking holes 30 provided in the annular plate 26 are substantially aligned with the arrangement of the magnets by a peripheral portion 30a having substantially the same shape as the cross section of the magnet of the rotor core. It was configured to be formed at each position. However, the peripheral edge portion 30a of the locking hole 30 does not necessarily have to have substantially the same shape as the cross section of the magnet, and if at least a portion matching the outer peripheral surface in the radial direction of each magnet is formed, Each magnet can be fixedly held by the annular plate 26 in response to an external force. In this case, the holding of each magnet in the circumferential direction and the radially inward direction is performed by the adjacent yoke 14.

[0017]

As is apparent from the above description, the present invention relates to a method in which a plurality of permanent magnets of a rotor core are mounted on at least one annular plate member inserted at a predetermined position between laminated structures of yoke members in the rotor core. At a position substantially matching each of
A plurality of locking holes, each of which has a peripheral edge portion capable of contacting at least a radial outer peripheral surface of these permanent magnets and through which a permanent magnet can be inserted, are formed so as to displace the plurality of permanent magnets radially outward. Is locked by the peripheral portion of each locking hole of the annular plate member, so that even when an outer hook for holding a permanent magnet cannot be formed on the yoke member of the rotor core,
A plurality of permanent magnets can be fixed and held against external force outward in the radial direction.Rigidity against centrifugal force and magnetic attraction during high-speed rotation is improved, and high operational reliability with excellent balance is achieved. A synchronous motor rotor is provided.

[Brief description of the drawings]

FIG. 1 is a side view of a rotor according to a first embodiment of the present invention,
A portion is shown in cross section along line II in FIG.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a front view of an annular plate member of the rotor of FIG. 1;

FIG. 4 is a view corresponding to FIG. 1 and is a partial sectional side view of a rotor according to a second embodiment of the present invention.

FIG. 5 is a view corresponding to FIG. 1 and is a partial sectional side view of a rotor according to a third embodiment of the present invention.

FIG. 6 is a view of a conventional rotor, in which (a) is a partial cross-sectional side view showing a part in a cross section taken along line aa of (b);
(B) is sectional drawing which followed the line bb of (a).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Rotating shaft 12, 34, 44 ... Magnet 14 ... Yoke 16, 36, 42 ... Rotor core 20 ... End plate 22 ... Tie rod 26 ... Ring plate 28 ... Insert hole 30 ... Locking hole

Claims (3)

(57) [Claims] 1. A rotating shaft, a plurality of permanent magnets radially arranged around the rotating shaft and extending in the axial direction, and the permanent magnets adjacent to each other by laminating thin plates of magnetic material in the axial direction. A rotor core having a plurality of yoke members disposed therebetween, each of which forms a magnetic pole of the rotor; and locking means for locking the plurality of permanent magnets at predetermined radial positions between the adjacent yoke members. Wherein the locking means is made of a non-magnetic material, is disposed at a central portion, and is inserted around the rotation shaft, and is disposed around the insertion hole. A plurality of locking holes into which the permanent magnets can be inserted, and at least one annular plate member inserted at a predetermined position between the laminated structures of the yoke members in the rotor core; The locking hole of the annular plate member is By the plurality of respective position substantially matching the permanent magnet of the stator core, formed through the circular ring plate member has a can abut the peripheral portion in at least a radial outer circumferential surface of the permanent magnet, the yoke A member is provided on the radially outer peripheral surface of the permanent magnet.
While having an engagement that does not form, the peripheral edge portion of said locking hole of said annular plate member, the rotor of the synchronous motor, characterized in that, to prevent displacement of the radially outwardly of the permanent magnet. (2) The peripheral edge of the locking hole of the annular plate member
Portion is formed by an outer peripheral portion that is continuous in the circumferential direction of the annular plate member.
The rotor of a synchronous motor according to claim 1, wherein the rotor is defined by: (3) The rotor has an axial direction of the rotor core.
The permanent magnet and the yoke member are disposed at
A pair of end plates for clamping, wherein the locking means is
Substantially aligned with each of the plurality of permanent magnets of the
A peripheral wall portion that can contact the outer peripheral surface of the permanent magnet
A plurality of locking recesses formed in each of the end plates.
The synchronous motor rotor according to claim 1 or 2, further comprising: